A new catalyst technology has developed which provides for the modification and/or control over the properties and characteristics of a polymer.
These new catalysts are referred to as bulky ligand transition metal catalysts which are formed from a bulky ligand transition metal compound and an activator. The bulky ligand of the transition metal compound may contain a multiplicity of bonded atoms, preferably carbon atoms and typically contain a cyclic structure such as, for example, a cyclopentadienyl ligand or a substituted cyclopentadienyl ligand, or any other ligand capable of .eta.-5 bonding to the transition metal. The transition metal is typically a Group 4, 5 or 6 transition metal or may be a metal from the lanthanide and actinide series. Other ligands may be bonded to the transition metal, such as but not limited to hydrocarbyl, halogen or any other anionic ligand. Generally, in the art, these bulky ligand catalysts are referred to as metallocene catalysts.
U.S. Pat. No. 5,308,817, herein incorporated by reference, discusses that storage of a metallocene/methylalumoxane solution at room temperature under nitrogen for several days resulted in gradual increases in polymer yields with specific syndiospecific metallocenes.
It would be highly desirable to have a process for producing higher activity polymerization catalyst systems that are independent of the bulky ligand transition metal catalyst component or metallocene.